What must a reviewer not do with the work under review unless they intend to co-sign it?

When a reviewer is evaluating a report, the key principle is that they should not sign the document unless they intend to co-sign it. Signing a report signifies agreement with its contents, conclusions, and methodology. By co-signing, the reviewer takes on the responsibility and liability associated with the appraisal report. Therefore, if a reviewer is not willing to co-sign, they should refrain from signing the work under review to maintain clarity regarding their level of responsibility.

Making changes to the report, submitting additional documents, or providing an oral report does not carry the same implications as signing. Reviewers can certainly suggest revisions, add supplementary information, or communicate findings verbally without assuming liability, as long as they do not sign the documentation. The essence of the question centers on the serious consequences that signing can entail, which indicates that this is the act that must be avoided unless there is a willingness to take on shared responsibility for the contents of the work.